Dear Gurgaon HR,
Many employers check their employees interest in social networking for an insight to grab details from these social sites like Facebook, Twitter, LinkedIn etc., Mostly they add their employees as good friends to determine the nature of the comments that you make or take from friends and family on the subject could reveal a lot more There is a loads more of personal information in these sites and is easily accessible, it's ain't not difficult for a company to learn minutiae about an induvidual without having to ask questions.
Giving a facebook id is quite feasible and social gathering over internet (employee should be cautious basically if his colleagues are already in there). Employer asking for any password is erroneous and one should not encourage the same by sharing any kind of password.